After I suspend/resume on my laptop, I get the login screen despite deleting the key in System > Preferences > Passwords and Encryption Keys > Passwords. After deleting the key, I will get no login screen until the next time I completely shut down my machine at which time it will resume requiring login after resuming following suspend. This seems unclear even to me, so feel free to ask for clarification.

What's puzzling is that if the machine puts itself to sleep when it's idle, upon resuming it doesn't ask for login.

Any ideas? This is fairly annoying since I normally open and close my notebook a dozen times a day and am accustomed to simply returning to work, not having to login again.